feat: automated backport robot and /test command

Signed-off-by: Alan Clucas <[email protected]>

.github/workflows/backport.yaml

@@ -0,0 +1,40 @@
+name: Backport merged pull request
+on:
+  pull_request_target:
+    types: [closed]
+  issue_comment:
+    types: [created]
+permissions:
+  contents: write # so it can comment
+  pull-requests: write # so it can create pull requests
+jobs:
+  backport:
+    name: Backport pull request
+    runs-on: ubuntu-latest
+
+    # Only run when pull request is merged
+    # or when a commment of `/backport` is created by someone other than the
+    # https://github.com/backport-action bot user (user id: 97796249).
+    if: >
+      (
+        github.event_name == 'pull_request_target' &&
+        github.event.pull_request.merged
+      ) || (
+        github.event_name == 'issue_comment' &&
+        github.event.issue.pull_request &&
+        github.event.comment.user.id != 97796249 &&
+        github.event.comment.author_association == 'MEMBER' &&
+        github.event.comment.body == '/backport'
+      )
+    steps:
+      - uses: actions/checkout@v4
+      - name: Create backport pull requests
+        uses: korthout/backport-action@be567af183754f6a5d831ae90f648954763f17f5 # v3.1.0
+        with:
+          label_pattern: ^backport/([^ ]+)$
+          pull_title: ${pull_title} [Backport ${target_branch}]
+          pull_description: |-
+            Automated backport of #${pull_number} to `${target_branch}`
+            Associated issues if any: [${issue_refs}]
+          experimental: |
+            {"conflict_resolution": "draft_commit_conflicts"}

.github/workflows/ci-build.yaml

@@ -8,6 +8,9 @@ on:
   pull_request:
     branches:
       - "main"
+      - "release-*"
+  issue_comment:
+    types: [created]
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -19,6 +22,15 @@ permissions:
 jobs:
   changed-files:
     name: Get changed files
+    if: >
+      (
+        github.event_name == 'issue_comment' &&
+        github.event.issue.pull_request != null &&
+        github.event.comment.author_association == 'MEMBER' &&
+        github.event.comment.body == '/test'
+      ) || (
+        github.event_name != 'issue_comment'
+      )
     outputs:
       # reference: https://github.com/tj-actions/changed-files#outputs-
       tests: ${{ steps.changed-files.outputs.tests_any_modified == 'true' }}

.github/workflows/docs.yaml

@@ -7,6 +7,9 @@ on:
   pull_request:
     branches:
       - main
+      - release/*
+  issue_comment:
+    types: [created]
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -18,6 +21,15 @@ permissions:
 jobs:
   docs:
     runs-on: ubuntu-24.04
+    if: >
+      (
+        github.event_name == 'issue_comment' &&
+        github.event.issue.pull_request != null &&
+        github.event.comment.author_association == 'MEMBER' &&
+        github.event.comment.body == '/test'
+      ) || (
+        github.event_name != 'issue_comment'
+      )
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - uses: actions/setup-python@0a5c61591373683505ea898e09a3ea4f39ef2b9c # v5.0.0

.spelling

@@ -139,7 +139,9 @@ args
 async
 auth
 backend
+backport
 backported
+backporting
 boolean
 booleans
 buildkit

docs/CONTRIBUTING.md

@@ -134,6 +134,15 @@ Subsequently, if there is still no response, it will be automatically closed as
 
 See the [Stale Action configuration](https://github.com/argoproj/argo-workflows/blob/main/.github/workflows/stale.yaml) for more details.
 
+## Automated actions
+
+As a member (see [roles](https://github.com/argoproj/argoproj/blob/main/community/membership.md)) of the argo-project you can use the following comments on PRs to trigger actions:
+
+* `/retest` - re-run any failing test cases
+* `/test` - trigger the full test suite.
+Only use this for PRs where the test suite has not automatically triggered - this is almost always wasteful and will not make things pass that `/retest` doesn't pass.
+* `/backport` - see [these instructions](releasing.md#backporting-fixes) for how to use automated backporting.
+
 ## Sustainability Effort
 
 Argo Workflows is seeking more [Reviewers and Approvers](https://github.com/argoproj/argoproj/blob/main/community/membership.md) to help keep it viable.

docs/releasing.md

@@ -1,5 +1,21 @@
 # Release Instructions
 
+## Backporting fixes
+
+Fixes can be backported using the automated cherry-picker.
+This will only work on merged commits, and always chooses the branches to backport based on labels.
+Label of the form `backport/<targetbranch>` will cherry-pick this commit to the given branch - e.g. `backport/release-3.6`.
+
+The backport will be triggered on merging, or on by adding a comment of `/backport`.
+You cannot specify the backport target using comment text, only a label.
+
+Backported commits can be backported, so it may make sense to backport the `release-3.6` backport to `release-3.5` for example.
+
+Backported fixes may fail on merge conflicts and assistance will be given by the bot on how to manually create a backport.
+
+Commits generated this way do not get automated CI, so use a comment of `/test` to run the test suite on them.
+They will need to be merged in the normal way, this part is not automated.
+
 ## Cherry-Picking Fixes
 
 ✋ Before you start, make sure you have created a release branch (e.g. `release-3.3`) and it's passing CI.